Use IsStreamError() and friends gMock matchers in quic/core (but not subdirectories).

gfe-relnote: n/a, test-only change.
PiperOrigin-RevId: 282792467
Change-Id: I827d913c14334b493b46977a827d44e72143fa4e
diff --git a/quic/core/quic_ietf_framer_test.cc b/quic/core/quic_ietf_framer_test.cc
index 725eb68..e4feb47 100644
--- a/quic/core/quic_ietf_framer_test.cc
+++ b/quic/core/quic_ietf_framer_test.cc
@@ -822,7 +822,7 @@
 
   // Now check that received == sent
   EXPECT_EQ(sent_frame.quic_error_code, sink_frame.quic_error_code);
-  EXPECT_EQ(sink_frame.quic_error_code, QUIC_NO_ERROR);
+  EXPECT_THAT(sink_frame.quic_error_code, IsQuicNoError());
   EXPECT_EQ(sink_frame.error_details, test_string);
   EXPECT_EQ(sink_frame.close_type, sent_frame.close_type);
   EXPECT_EQ(sent_frame.close_type, IETF_QUIC_TRANSPORT_CONNECTION_CLOSE);